Field
The present disclosure relates to techniques for communicating in downhole environments. More particularly, the present disclosure relates to tools for communicating with a distributed network of wireless communication devices.
Description of the Related Art
Hydrocarbon fluids, including oil and natural gas, can be obtained from a subterranean geologic formation, referred to as a reservoir, by drilling a wellbore that penetrates the formation. Once a wellbore is drilled, various well completion components are installed to enable and control the production of fluids from the reservoir. Data representative of various downhole parameters, such as downhole pressure and temperature, are often monitored and communicated to the surface during operations before, during and after completion of the well, such as during drilling, perforating, fracturing and well testing operations. In addition, control information often is communicated from the surface to various downhole components to enable, control or modify the downhole operations.
Accurate and reliable communications between the surface and downhole components during operations can be difficult. Wired, or wireline, communication systems can be used in which electrical or optical signals are transmitted via a cable. However, the cable used to transmit the communications generally has complex connections at pipe joints and to traverse certain downhole components, such as packers. In addition, the use of a wireline tool is an invasive technique which can interrupt production or affect other operations being performed in the wellbore. Thus, wireless communication systems can be used to overcome these issues.
In a wireless system, information is exchanged between downhole components and surface systems using acoustic or electromagnetic transmission mediums. As an example, a network of acoustic devices can be deployed downhole that uses the tubing as the medium for transmitting information acoustically. To ensure that communications from all devices reach the surfaces, an acoustic network is generally arranged as a series of repeaters. That is, communications from devices furthest from the surface are received and passed on by neighboring devices that are closer to the surface. Likewise, communications from the surface that are directed to the furthest removed devices are received and passed on by intermediate devices. Because of this series arrangement where the communication path is dependent on neighboring devices, a single point of failure can disrupt the communications network.